1. Field of Invention
This invention relates to energy converters. Specifically, the present invention relates to devices, such as photodetectors, photoconductors, and arrays thereof, for converting incident electromagnetic energy into plasma waves and/or electrical signals.
2. Description of the Related Art
Energy detectors are employed in various demanding applications including digital cameras, missile-guidance systems, motion detectors, radar receivers, microwave dishes, and other types of antennas. Such applications often demand efficient detectors that can effectively absorb incoming energy and provide a corresponding electrical signal with minimal noise and energy loss.
High-performance detectors are particularly important in detector-array applications used for imaging applications, where detector performance greatly affects image quality. An example detector array includes several closely spaced photodiodes. Incident light causes the photodiodes to output electrical current representative of the incident light. The conversion from light to electricity is called phototransduction, and a photodiode detector is often called a phototransducer.
Incident light on a detector surface yields electron-hole pairs in the detector, which result in the electrical current. Unfortunately, certain electron-hole pairs are generated via heat or other processes, and certain electron-hole pairs spontaneously combine. These processes contribute to noise or output signal degradation.
To reduce noise associated with a given detector in a detector array, detectors are shrunk. Unfortunately, as the size and spacing between detectors in an array decrease, the detectors may become less efficient at absorbing specific wavelengths of electromagnetic energy. Furthermore, interference or cross_talk between detectors may increase. Such factors have limited minimum detector sizes. Unfortunately, large detectors may undesirably limit resolution of accompanying imaging systems.
To further tune the performance of a detector array, certain polarization filters, waveguides, or other optics are positioned in front of the detector array. However, such mechanisms are often prohibitively expensive and may introduce undesirable artifacts in the resulting array output.
Hence, a need exists in the art for a versatile, low-noise, small detector that may reduce or eliminate the need for expensive filters and optics and that may increase the resolution and performance of an accompanying detector array.